Well this is less a tutorial, more of a this is what I have done and this is how well it worked. I have been building my robot using the Vishay Si9986 Buffered H-Bridge IC’s and have come across some issues – mainly with back emf which is the silent killer when it comes to motor driver chips.

Here is the schematic of the setup as it currently is:

Si9986 Schematic

This follows my normal setup – uses the least amount of control lines, and is fairly simple to code for. Everything was going fine until it stopped moving: the current hypothesis is that the Vishay chip does not have high enough rated flyback diodes (the snubber circuit), so the advice is to make sure you include your own snubber circuit if you are using a Si9986 close to (half) its operating limits…